Heat recovery from outer surface of cement production rotary kiln comprises passing air or raw material powder or sludge through an annular gap between the kiln and a concentric outer cylinder

摘要

Heat recovery from a rotary kiln outer surface (1.3) involves passing air or raw material powder or sludge through an annular gap defined between the kiln and a concentric outer cylinder (1.5). Radiant heat is recovered from a rotary kiln outer surface (1.3) by positioning a cylinder (1.5) concentrically and at a certain spacing about the outer cylindrical casing (1.3) of the kiln (1.1), inserting a spiral strip (1.13) of certain pitch in the resulting annular gap (1.4), positioning an air suction hood (1.7) on the cylinder at the kiln inlet end and optionally an air exhaust hood (1.14) at the opposite end of the cylinder and drawing air through the sealed annular gap. An Independent claim is also included for heat is recovered from a rotary kiln outer surface by conveying raw material powder or sludge through an annular gap defined between the rotary kiln and a concentric outer cylinder.